New Post: SPCascadeDropdowns give me a "postback error"

The code above is the code working and not working, as I said it's the same.

The word "Plage" here is not referring to beaches, much more like "Time Slot". But if you want nice beaches, come in France :p.

I'll explain the context a little and try to translate the french words (I keep the french words for the "logic" purpose), I'm actually working an Intranet for a General Hospital, where there are 3 sites (3 différent building across the city), each sites have specific time slots (Example Site1 have Morning and Afternoon but not Night, however Site2 have the 3 choices).

The list "PlagesHoraires" that I'm using is composed of :

• Titre (LinkTitle, single line of text, this column is not used and hidden)
• Site (search column which refers to the Sites list)
• Plage (search column which refers to another list "PlageJournee" where we can found the 3 time slots Matin (Morning), Après-midi (Afternoon) and Nuit (Night) with their hours)
• Plage:Début (column I get from the search column, which refers to the start of the time slot)
• Plage:Fin (column I get from the search column, which refers to the end of the time slot)
  

In my 2 lists ("CR Permanence" and "Synthèse") I have to select a Site and then select a "Plage Horaire" (time slot).
The "Site" column and "Plage Horaire" column are named exactly the same in both lists (so I don't have to change the code).
I used the SPCascadeDropdowns to get in my "Plage Horaire (time slot) dropdown only these which match with de Site selected before.
I do the same in the 2 lists.

So I created a CustomNewForm.aspx and CustomEditForm.aspx, in these 2 lists. I tried the form before adding the SPCascadeDropdowns code, it works fine on the 2 lists.
I added the code in both forms, it works fine for "CR Permanence" but not for "Synthèse" where I get the postback error.
I tried to recreate from scratch the list, but it's inconclusive, I get the same error.

I hope you understand my explanation.

Yoann.